The article presents the results of genotyping and determination of viral load in newborns with various forms of congenital cytomegalovirus infection. A retrospective analysis of clinical manifestations and results of laboratory examination of 50 children with congenital CMVI was carried out. The regions UL55, UL73, UL75 of glycoproteins B, N, H of CMV isolated from children with congenital CMVI were sequenced. The analysis showed the absence of a reliable association of viral load with the severity of the disease: in children with a mild course, the replicative activity of the virus was 9 times higher than in children with a moderate form of congenital CMVI (p = 0.011). Sequencing of the nucleotide sequences of the UL55 (gB) gene revealed 5 genotypes with a predominance of gB7 (60.0%). In the region of the UL73 gene, 6 genotypes were identified (gN1, gN2, gN3a, gN3b, gN4b, gN4c), gN4c was dominant (33.3%). 2 genotypes were found in the UL75 region: gH1 and gH2 (50.0%). When comparing the results of genotyping and clinical manifestations of the disease, a significant predominance of gB7 and gH2 genotypes (p = 0.049 and p = 0.027, respectively) was found in central nervous system pathology, including the development of meningoencephalitis.

This article presents the results of a study aimed at identifying the clinical, anamnestic, and laboratory features of bacterial and viral meningitis in children on the first disease days. Materials and Methods: This prospective study included 37 children with etiologically confirmed meningitis (bacterial purulent (n = 20) and viral (n = 17) and 26 children with meningism. Following standardized protocols, the medical histories data, results of physical examination, and laboratory tests (blood and CSF) were obtained. ROC curve analysis was performed, and a predictive model was constructed using binary logistic regression. Results: The duration of general cerebral symptoms as the first signs of meningitis syndrome was: in group №1 — 1.0 [1.0—2.0], №2 — 1.0 [1.0—3.0], №3 — 2.0 [1.0—4.0] days (p = 0.309). Altered level of consciousness increased the odds (odds ratio) of bacterial etiology by 17.5 times (95% CI 3.016—101.54). The following symptoms were sensitive for the meningitis in the first days: neck stiffness (Se = 89.2%; Sp = 38.5%), the «seating» symptom (Se = 77.8%; Sp = 44.0%). There were no significant differences in meningeal symptoms in the early stages of the disease between viral and bacterial meningitis. Laboratory tests of bacterial meningitis in our study were characterized by high C-reactive protein levels and neutrophilic leukocytosis with lymphopenia. In the first days of general cerebral symptoms of bacterial meningitis, elevated CSF lactate concentrations (> 3.45 mmol/L) (Se = 80%, Sp = 100%) are typical. Conclusions: The clinical presentation of acute meningitis in the early stages exhibits typical symptoms of varying severity. However, physical examination alone does not allow for a clear differentiation of the etiology, necessitating the search for sensitive and specific laboratory markers for differential diagnosis.

Aminotransferases reflect the volume and degree of liver damage with the development of inflammation in chronic hepatitis C, correlate with fibrosis, therefore their determination in such patients is of both scientific and practical importance. The aim of the study is determination of the clinical course, dynamics of laboratory and instrumental parameters in children with HCV who received direct antiviral therapy, depending on the initial level of aminotransferases in blood serum. Materials and methods. 36 patients aged 3—16 years were under observation, randomized depending on the level of aminotransferases in the blood serum. All children underwent a regulated clinical, laboratory and instrumental examination before starting treatment with the direct antiviral drug glecaprevir/pibrentasvir, 12 weeks and 6 months after the start of the course of therapy. Results. Patients with high levels of aminotransferases were more likely to become infected with HCV perinatal compared with children with normal levels of these enzymes in the blood serum. The age and clinical symptoms in both groups did not differ. Aminotransferases were initially elevated in 27.8% of children with chronic hepatitis C, while their maximum level did not exceed 4 norms. The appointment of a course of direct antiviral therapy with glecaprevir / pibrentasvir contributes to a fairly rapid and stable normalization of aminotransferase levels in all patients in both groups, regardless of their initial amount. HCV genotype 1b prevailed in both children with high levels of aminotransferases and those with normal levels, and the viral load was low in the group with normal levels of aminotransferases. Faster normalization of liver size according to ultrasound data in patients with normal aminotransferase levels under the influence of direct antiviral therapy indicates a direct correlation between the level of aminotransferases and the degree of liver damage in chronic hepatitis C. However, more pronounced fibrosis in 1 child (up to grade F3 on the METAVIR scale) in this group indicates the need for close attention even to those children whose aminotransferase levels remain normal, which does not exclude the course of their fibrotic process in the liver. Conclusion. Thus, it can be assumed that the baseline level of aminotransferases in children with HCV is important for assessing the degree of liver damage and allows predicting the effectiveness of direct antiviral therapy.

Objective: to study the epidemiological and clinical-laboratory features of the course of atypical pneumonia in children who were inpatients at the «City ClinicalHospital No. 7 of the Ministry of Health of the Udmurt Republic» in dynamics over 5 years (2020—2024). Materials and methods: A retrospective analysis of176 medical records of children aged 4 months to 17 years 11 months 29 days was conducted. Of the 176 children, 106 had atypical pneumonia, and 70 hadtypical pneumonia. Results: The epidemiological features of atypical pneumonia are manifested by a clear annual increase in incidence from August to December,with the maximum incidence observed in 2020. Atypical pathogens are a common cause of community-acquired pneumonia. Mycoplasma pneumonia was thepredominant etiology of this disease. Patients have a characteristic epidemiological history (contact with individuals with similar symptoms in organized groups), anacute onset of the disease with fever and frequent nonproductive cough, but without severe intoxication. Conclusion. Atypical pneumonia is one of the causes ofprolonged nonproductive cough in school-aged children and adolescents, which requires increased alertness of specialized specialists.

In different countries, arthritis occurs with a frequency of 0.6 to 27 per 100,000. Any pediatrician has encountered arthralgias and arthritis in his work. Infections are not the least among the causes of arthritis. If we talk about arthritis that can develop on the background or after infections, then these will be, first of all, reactive arthritis and arthritis associated with infections. They are united by the possibility of detecting an etiological agent, which in turn allows the use of etiotropic therapy. Unfortunately, infectious arthritis in children is not described enough in the available literature. The greatest attention is paid to reactive arthritis. While little has been written about the rest. Materials and methods: a review of the most relevant domestic and foreign literature on infectious arthritis in children has been conducted. Results: infectious arthritis can develop both against the background of an acute infection, and weeks and months after its end. Based on the clinic alone, it is difficult to assume the etiology of the disease. An accurate diagnosis will be made by modern laboratory and instrumental examination methods.

It has been proven that the SARS-CoV-2 virus can initiate the development of a number of post-infectious complications in children, including cardiovascular and thrombotic complications, which are clearly demonstrated in the clinical case of heart transplantation, which is an extremely relevant practice for doctors of all specialties. Objective: to describe a clinical case of heart transplantation in a child who had COVID-19. The article presents a general understanding of the pathogenetically bidirectional relationship between the new coronavirus infection and cardiovascular complications, and provides a clinical case of heart transplantation in a 17-year-old child who had COVID-19. The clinical case we presented confirms the existence of a pathogenetically determined relationship between COVID-19 and cardiovascular complications. To better understand the mechanisms underlying the development of cardiovascular disorders, it is necessary to create a unified Global Registry of patients with cardiac complications after COVID-19.

Legionellosis is a bacterial infection that affects the respiratory tract, lung tissue, and a number of other organs and systems. Legionella pneumonia is characterised by the most severe course, in most cases accompanied by extensive inflammation. Despite the relative rarity of the pathology, especially in young patients, cases of Legionnaires' disease pneumonia in paediatric practice are of considerable scientific and clinical interest. Their thorough study is crucial for improving early diagnosis, optimising treatment, and shifting the clinical spectrum towards a predominance of mild forms of the disease. The aim of this study is to summarise current data on Legionnaires' disease and to present two clinical observations of Legionnaires' pneumonia. Аn analysis of the medical records of the only two cases of confirmed Legionnaires' disease in children aged 10 months and 2.5 years in the last 3 years, who were hospitalised in a multidisciplinary children's hospital with an infectious disease profile, was carried out; The world medical literature on Legionnaires' disease was studied using search engines and databases such as eLibrary, PubMed, ResearchGate, Google Scholar, and Scopus.

The relevance of opisthorchiasis is due to its widespread prevalence in the wild in Russia and its ability to infect humans through the consumption of improperly cooked fish. The aim of this paper is to present available literature data on the epidemiology, clinical and laboratory manifestations, and diagnosis of opisthorchiasis, illustrated by a clinical example. This paper also presents an alternative theory for the hematogenous path of parasite migration in the definitive host. Materials and Methods: A review of recent Russian and international literature, including online resources, was conducted on the situation with opisthorchiasis in Russia and Moscow, as well as the pathogenesis of opisthorchiasis. A clinical observation of a patient with imported opisthorchiasis in Moscow was presented. Conclusion. The diagnosis of opisthorchiasis is based on the epidemiological history, clinical presentation, eosinophilia, and detection of multiple inflammatory foci in the liver. This diagnosis is confirmed by coproovoscopic and serological methods. Focal changes in the liver parenchyma can be explained by the hematogenous migration of opisthorchis larvae.

Vulvovaginitis is the most common gynecological pathology in prepubertal girls, characterized by a high incidence rate (up to 93%) and a tendency to recur (up to 60%). The multifactorial nature of the disease and the non-specific clinical presentation create significant challenges for differential diagnosis. Objective: To systematize modern algorithms for the differential diagnosis of vulvovaginitis in girls to optimize the work of pediatricians and pediatric gynecologists at the outpatient stage. Materials and Methods: A review of current domestic and foreign literature sources, clinical guidelines, and protocols for the management of vulvovaginitis in childhood was conducted. Results: The article details the pathophysiological basis of vulvovaginitis, which are determined by the anatomical and physiological characteristics of girls. A classification of etiological factors is presented, distinguishing between non-specific (70—80% of cases) and specific causes. For the main disease entities, pathognomonic clinical features and recommended diagnostic methods are summarized in a comparative table. Conclusion: Effective diagnosis of vulvovaginitis in children requires a comprehensive multidisciplinary approach. Strict adherence to a structured diagnostic algorithm makes it possible to identify the cause of inflammation, prescribe adequate therapy, and avoid diagnostic errors.

Essential thrombocythemia (ICD-10: D47.3, OMIM: #187950) is a rare clonal myeloproliferative disorder characterized by a persistent increase in platelet count. The clinical course in newborns and young children is predominantly asymptomatic or oligosymptomatic, with a paradoxically low risk of thrombotic complications against a background of a high frequency of microvascular and haemorrhagic disorders caused by acquired von Willebrand syndrome. The diagnosis of essential thrombocythemia is complicated by the need to exclude reactive thrombocytosis and its hereditary forms, which are more common in the neonatal period. A promising direction at the moment is the development of paediatric diagnostic criteria and comprehensive genetic analyses to identify new driver mutations. Treatment is conservative and often leads to a favourable outcome. This review systematises current data from the world literature on the characteristics of essential thrombocythemia in newborns and young children, focusing on key differences from the adult form of the disease.

This article presents two clinical cases of visceral leishmaniasis (VL) in children under 5 years of age, one of which was complicated by hemophagocytic syndrome (HPS). Both cases illustrate the diagnostic challenges encountered in non-endemic regions, where VL may mimic malignancies, hematologic, or infectious diseases. The authors describe the diagnostic algorithm involving bone marrow microscopy, molecular (PCR) testing, and differential diagnosis. The treatment strategies included amphotericin B therapy and immunomodulatory treatment (dexamethasone and intravenous immunoglobulin) for VL with HPS complications. The article emphasizes the need to raise clinical awareness in non-endemic areas and to expand access to sensitive diagnostic methods to ensure timely identification of VL and prevent severe outcomes.

The article presents the clinical case of severe Cl. difficile-associated diarrhea in a three-year-old child suffering from atopic dermatitis and cow’s milk protein allergy. Clinical manifestations of the disease included fever, bloody diarrhea, and abdominal pain. Diagnosis was established based on medical history, clinical presentation, negative results from ELISA, PCR, and microbiological stool tests for viral and bacterial pathogens causing intestinal infections, along with a positive stool test for toxins A and B produced by Cl. difficile, confirmed by prompt improvement after initiation of vancomycin therapy. Within three days of the child being discharged from the hospital, symptoms of hemorrhagic colitis recurred. Upon readmission, stool testing for toxins A and B of Cl. difficile yielded negative results; however, given the clinical and epidemiological context, including the potential for false negatives, antibacterial therapy with vancomycin was initiated again. Treatment resulted in complete resolution of symptoms and normalization of the child’s general condition. Over the next year of follow-up, there were no signs of gastrointestinal injury or recurrence, suggesting successful treatment and recovery of normal bowel function. Analysis of this case highlighted challenges in diagnosing and managing Cl. difficile infection, which could be addressed by implementing the following strategies: when initial screening for toxins A and B of Cl. difficile in fecal specimens produces negative results via enzyme-linked immunosorbent assays (ELISAs), additional testing utilizing more reliable methods such as toxicigenic culture isolation should proceed. This involves adopting multistep diagnostic algorithms as suggested by current guidelines. Additionally, treatment approaches must be tailored individually, accounting for all relevant risk factors and specifics of each patient’s health profile.

Moscow, December 8-9, 2025